fs: move mapping helpers

commit a793d79ea3e041081cd7cbd8ee43d0b5e4914a2b upstream.

The low-level mapping helpers were so far crammed into fs.h. They are
out of place there. The fs.h header should just contain the higher-level
mapping helpers that interact directly with vfs objects such as struct
super_block or struct inode and not the bare mapping helpers. Similarly,
only vfs and specific fs code shall interact with low-level mapping
helpers. And so they won't be made accessible automatically through
regular {g,u}id helpers.

Link: https://lore.kernel.org/r/20211123114227.3124056-3-brauner@kernel.org (v1)
Link: https://lore.kernel.org/r/20211130121032.3753852-3-brauner@kernel.org (v2)
Link: https://lore.kernel.org/r/20211203111707.3901969-3-brauner@kernel.org
Cc: Seth Forshee <sforshee@digitalocean.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
CC: linux-fsdevel@vger.kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Seth Forshee <sforshee@digitalocean.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Christian Brauner
2022-06-28 14:16:10 +02:00
committed by Jaegeuk Kim
parent 6a373411de
commit d3880474de
8 changed files with 108 additions and 90 deletions

View File

@@ -41,6 +41,7 @@
#include <linux/stddef.h>
#include <linux/mount.h>
#include <linux/cred.h>
#include <linux/mnt_idmapping.h>
#include <asm/byteorder.h>
#include <uapi/linux/fs.h>
@@ -1626,34 +1627,6 @@ static inline void i_gid_write(struct inode *inode, gid_t gid)
inode->i_gid = make_kgid(inode->i_sb->s_user_ns, gid);
}
/**
* kuid_into_mnt - map a kuid down into a mnt_userns
* @mnt_userns: user namespace of the relevant mount
* @kuid: kuid to be mapped
*
* Return: @kuid mapped according to @mnt_userns.
* If @kuid has no mapping INVALID_UID is returned.
*/
static inline kuid_t kuid_into_mnt(struct user_namespace *mnt_userns,
kuid_t kuid)
{
return make_kuid(mnt_userns, __kuid_val(kuid));
}
/**
* kgid_into_mnt - map a kgid down into a mnt_userns
* @mnt_userns: user namespace of the relevant mount
* @kgid: kgid to be mapped
*
* Return: @kgid mapped according to @mnt_userns.
* If @kgid has no mapping INVALID_GID is returned.
*/
static inline kgid_t kgid_into_mnt(struct user_namespace *mnt_userns,
kgid_t kgid)
{
return make_kgid(mnt_userns, __kgid_val(kgid));
}
/**
* i_uid_into_mnt - map an inode's i_uid down into a mnt_userns
* @mnt_userns: user namespace of the mount the inode was found from
@@ -1682,68 +1655,6 @@ static inline kgid_t i_gid_into_mnt(struct user_namespace *mnt_userns,
return kgid_into_mnt(mnt_userns, inode->i_gid);
}
/**
* kuid_from_mnt - map a kuid up into a mnt_userns
* @mnt_userns: user namespace of the relevant mount
* @kuid: kuid to be mapped
*
* Return: @kuid mapped up according to @mnt_userns.
* If @kuid has no mapping INVALID_UID is returned.
*/
static inline kuid_t kuid_from_mnt(struct user_namespace *mnt_userns,
kuid_t kuid)
{
return KUIDT_INIT(from_kuid(mnt_userns, kuid));
}
/**
* kgid_from_mnt - map a kgid up into a mnt_userns
* @mnt_userns: user namespace of the relevant mount
* @kgid: kgid to be mapped
*
* Return: @kgid mapped up according to @mnt_userns.
* If @kgid has no mapping INVALID_GID is returned.
*/
static inline kgid_t kgid_from_mnt(struct user_namespace *mnt_userns,
kgid_t kgid)
{
return KGIDT_INIT(from_kgid(mnt_userns, kgid));
}
/**
* mapped_fsuid - return caller's fsuid mapped up into a mnt_userns
* @mnt_userns: user namespace of the relevant mount
*
* Use this helper to initialize a new vfs or filesystem object based on
* the caller's fsuid. A common example is initializing the i_uid field of
* a newly allocated inode triggered by a creation event such as mkdir or
* O_CREAT. Other examples include the allocation of quotas for a specific
* user.
*
* Return: the caller's current fsuid mapped up according to @mnt_userns.
*/
static inline kuid_t mapped_fsuid(struct user_namespace *mnt_userns)
{
return kuid_from_mnt(mnt_userns, current_fsuid());
}
/**
* mapped_fsgid - return caller's fsgid mapped up into a mnt_userns
* @mnt_userns: user namespace of the relevant mount
*
* Use this helper to initialize a new vfs or filesystem object based on
* the caller's fsgid. A common example is initializing the i_gid field of
* a newly allocated inode triggered by a creation event such as mkdir or
* O_CREAT. Other examples include the allocation of quotas for a specific
* user.
*
* Return: the caller's current fsgid mapped up according to @mnt_userns.
*/
static inline kgid_t mapped_fsgid(struct user_namespace *mnt_userns)
{
return kgid_from_mnt(mnt_userns, current_fsgid());
}
/**
* inode_fsuid_set - initialize inode's i_uid field with callers fsuid
* @inode: inode to initialize